Mounting element for a high-temperature oven

Description

[0001] The present invention relates to a holding element for a high-temperature furnace having the features of the preamble of claim 1.

[0002] In the context of this application, high-temperature furnaces refer to electrically heated furnaces, such as those described in AT 16 588 U1, which are designed for operating temperatures greater than 600°C. In particular, the invention is directed to applications with operating temperatures greater than 800°C.

[0003] High-temperature furnaces are typically heated by passing current through heating elements supported by a heating element suspension and releasing heat into a process chamber.

[0004] This is usually achieved by a support structure extending from a shield into the process chamber. The support structure can be designed, for example, as a bolt or a profile. A heating conductor suspension is attached to the support structure—which is also electrically connected to the shield—via an electrically insulating retaining element. The one or more heating conductors are ultimately supported by the heating conductor suspension.

[0005] A holding element in the context of the present application therefore has the task of mechanically connecting a heating conductor suspension to a support structure and simultaneously electrically insulating the heating conductor suspension from the support structure. It is known to design holding elements as ceramic sleeves that are inserted into the support structure.

[0006] During the operation of high-temperature furnaces, evaporation of heat-treated material regularly occurs, resulting in deposits of the evaporated material. Deposits of such evaporation of heat-treated material on a support element reduce the electrical insulation effect and even lead to electrical conductivity, which can result in a short circuit between the heating conductors and the support structure or shielding.

[0007] To remedy this problem, cleaning annealing must be performed, or contaminated retaining elements must be replaced early. This causes high costs, plant downtime, and increased energy consumption.

[0008] The object of the present invention is to provide an improved holding element. In particular, the electrical insulating effect of the holding element is to be maintained more effectively over the service life of the high-temperature furnace. It is particularly desirable for the holding element to retain its electrical insulating effect even after undergoing vapor deposition.

[0009] The object is achieved by a holding element having the features of claim 1. Preferred developments are defined in the dependent claims.

[0010] By a holding element with: at least one fastening section formed on a part of a surface of the holding element for mechanically connecting the holding element to a support structure, at least one heating conductor receiving section formed on a part of the surface of the holding element for receiving a heating conductor, wherein at least one groove with a depth and a width is formed on a circumferential part of the surface of the holding element lying between the fastening section and the heating conductor receiving section, which groove extends substantially over the entire circumference of the circumferential part of the surface and at least one imaginary path between the fastening section and the heating conductor receiving section crosses the at least one groove along the surface of the holding element, wherein a groove has an aspect ratio formed from the ratio of the depth to the width of greater than or equal to 1.5, The electrical insulating effect of the holding element is retained even in the event of undesired contamination of a surface of the holding element.

[0011] In the holding element according to the invention, the formation of a continuous electrically conductive path is effectively prevented by the deposition of electrically conductive deposits.

[0012] The groove can be realized in various geometric forms. Functionally, the design of the groove follows the principle that the shape of the groove shades the groove contour, preventing precipitation from accumulating. In particular, the groove base does not experience precipitation.

[0013] This prevents the occurrence of a continuous electrically conductive path across the groove.

[0014] The term "substantially" extending around the entire circumference of the peripheral portion of the surface means that the groove is largely continuous.

[0015] Preferably, the groove is completely continuous, thus forming a closed ring along the circumference of the retaining element. The uninterrupted design particularly effectively prevents the formation of a continuous electrically conductive path.

[0016] The "circumferential part" of the surface means that the groove is formed on a portion of the surface that forms a circumferentially closed surface section. Moving in one direction along the circumferential part of the surface returns you to the starting point. Technically, the feature of the groove being formed on a circumferential part of the surface means that the groove can actually form an effective interruption between the fastening section and the heating conductor receiving section.

[0017] Shapes of the retaining element are conceivable in which the groove is not 100% continuous, for example, because a certain section of the retaining element's surface is protected from coating by other measures. In such locations, it would not be absolutely necessary for the groove to extend continuously. Therefore, in this context, "essentially" is understood to mean that the groove extends over ≥ 80% of a circumference, preferably over ≥ 90%.

[0018] Circumference is a distance along the surface that leads back to the starting point.

[0019] As a rule, however, and preferably, the groove extends completely continuously, i.e. without interruption, over the surrounding part of the surface.

[0020] Typically and preferably, the groove extends entirely along an outer surface of the retaining element, since any deposition of a precipitate occurs mainly on outer and exposed surfaces.

[0021] The fastening section allows for a mechanical connection of the holding element to a supporting structure. The connection can be made directly or indirectly, for example, via a connecting element.

[0022] The fastening section can take on a wide variety of forms. For example, it can be a surface section of the holding element that is shaped so that it can be inserted or inserted into a corresponding receptacle in a support structure. Alternatively or additionally, the mechanical connection to the support structure can be force-fitting and / or form-fitting via a connecting element. The fastening section can therefore also form a receptacle for a connecting element or contain such a receptacle. The support structure can be designed, for example, as a bolt or as a profile. It is also conceivable for the shielding itself to allow a connection of the holding element, for example by having a - possibly reinforced - recess in the shielding. In this case, the shielding itself functions as the support structure.

[0023] A portion of the surface of the holding element is formed as a heating conductor receiving section for directly or indirectly receiving a heating conductor. The heating conductor receiving section, which is different from the fastening section, is spatially spaced from the fastening section. In other words, the fastening section is formed at least partially on a different area of ​​the surface of the holding element.

[0024] An indirect or direct reception of a heating conductor means that the heating conductor can be received via an auxiliary structure, for example a heating conductor holder, or in the case of a direct reception, that the heating conductor receiving section directly holds the heating conductor or a heating conductor supply line.

[0025] In particular, it is provided that the heating conductor receiving section at least partially encompasses a heating conductor holder or a heating conductor to ensure secure positioning. For example, the heating conductor receiving section can form a feedthrough for a heating conductor or a heating conductor supply line. A heating conductor supply line is considered to be part of the heating conductor.

[0026] Preferably, it can be provided that the heating conductor receiving section and / or the heating conductor holder allow thermal expansion of the heating conductor holder and / or the heating conductor by providing play.

[0027] A portion of the surface of the holding element lies between the fastening section and the heating conductor receiving section. The fastening section and the heating conductor receiving section are also electrically separated from each other, i.e., insulated, by the surface section in between.

[0028] The holding element is designed such that an imaginary path between the fastening section and the heating conductor receiving section along the surface of the holding element crosses the at least one groove.

[0029] In other words, a connection between the fastening section and the heating conductor receiving section is always interrupted by a groove along the surface. This arrangement of at least one groove ensures that a potential current path crosses at least one groove. This arrangement, together with the actual design of the groove, ensures an interruption of the potential current path.

[0030] To achieve the technical effect, it is intended that a groove has an aspect ratio, formed from the ratio of depth to width, of greater than 1.5. More preferably, the aspect ratio is greater than 3, and even more preferably greater than 5. A particularly advantageous combination has been found, for example, in a groove width of approximately 0.5 mm and a groove depth of 3 mm, which corresponds to an aspect ratio of 6.

[0031] The aspect ratio thus describes the elongation or slenderness of the groove. The higher the aspect ratio, the more effective the shading effect of the groove. Aspect ratios greater than 10 provide little additional effect, since the groove base is then generally no longer reached by precipitation anyway. Therefore, the aspect ratio is preferably ≤ 10.

[0032] The depth of the groove is determined by the distance of the groove base from the surface of the holding element.

[0033] If the cross-sectional shape of the groove deviates from a rectangular shape, a smallest width can be used to determine the aspect ratio.

[0034] Preferably, the groove has a depth of at least 1 mm, which significantly reduces the shadowing of groove flanks and / or a groove base compared to deposition. Below this depth, i.e., if the groove is too shallow, the formation of a continuous electrically conductive path may not be effectively prevented.

[0035] The groove width is preferably at least 0.25 mm. If the groove is too narrow, the deposited precipitates could bridge the groove flanks.

[0036] Preferably, a plurality of grooves is formed, in particular two or three grooves. The formation of a plurality of grooves is helpful for reliably preventing the formation of a continuous electrically conductive path.

[0037] Preferably, a groove has a depth between 3 mm and 10 mm. With a depth according to this refinement, shading of the groove flanks and / or a groove base is advantageously ensured. Even greater depths do not provide much in terms of shading, but are generally more difficult to manufacture and / or structurally weaken the retaining element.

[0038] Preferably, a groove has a width between 0.25 mm and 3 mm. These values ​​have proven particularly favorable: if the width is less than 0.25 mm, bridging of the groove flanks may occur. Widths over 3 mm may, depending on exposure, groove depth, etc., lead to a deposit forming a conductive path in the groove. Widths in a range between 0.5 mm and 2 mm are even more preferred.

[0039] Preferably, it can be provided that a groove has an undercut at least in sections, as a result of which undercut, at least in sections, a first free groove cross-section at a first distance from the surface is smaller than a second free groove cross-section at a second distance from the surface, wherein the first distance is smaller than the second distance. This means that in the groove there is at least in sections a narrower point compared to the adjacent cross-section of the groove. This can, for example, further reduce precipitation after the undercut. "After" with regard to the undercut means "deeper", i.e. at positions further away from the surface.

[0040] Preferably, the groove can be provided with a widening at least in some sections, which widens the free groove cross-section at least in some sections. The wall of such a widening is particularly inaccessible to precipitation. Thus, such a widening can also contribute to preventing a continuous electrically conductive path.

[0041] Preferably, the groove can have a main direction of extension that deviates at least at one point from the direction of the plane normal at that one point on the surface of the retaining element where the groove is formed. This means that in this preferred embodiment, the groove does not run vertically, but rather, deviating from the vertical, extends obliquely into the retaining element. This offers the particular advantage that the shading effect of the groove against precipitation is further improved.

[0042] A particularly advantageous design is one in which the groove base is geometrically no longer reached by a beam incident vertically into the groove. The above-mentioned undercuts and flares, as well as the angled profile, can be realized particularly elegantly using additive manufacturing processes.

[0043] Preferably, the retaining element is monolithic, i.e., formed in one piece. A single piece offers several advantages: multiple functions can be integrated into a single component. The electrical insulation effect is more predictable than, for example, with stacked individual panes. Furthermore, assembly is easier.

[0044] For example, if the retaining element is made of individual rings assembled together, the gap between the rings could change during heating, thus compromising the functionality of the retaining element. Maintaining the gap dimensions would require preloading with springs, for example, which is problematic in the long run in high-temperature applications. In contrast, a monolithic solution is advantageous in terms of functionality and durability.

[0045] In a further development, the retaining element is designed as a feedthrough through a shield. Here, the retaining element is designed to be inserted into or through the shield. In an installed situation, the retaining element acts as an electrically insulating sleeve in the shield, with the shield acting as a supporting structure.

[0046] The retaining element of this refinement allows for the electrically insulated passage of a heating connection, i.e., an electrical supply line, through the shielding. This eliminates the need for separate electrical insulation for this electrical supply line.

[0047] In one embodiment of this further development, the holding element is a ceramic sleeve, such as a hollow cylinder, wherein a groove is formed on at least one of its end faces as discussed above.

[0048] The holding element is preferably made of a high-temperature-resistant ceramic. Particularly suitable are technical ceramics such as aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ), silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), and mixtures of technical ceramics.

[0049] "Consisting" here means that the significant portion is made up of the respective ceramic. More preferably, the retaining element consists of ≥ 98% of the respective technical ceramic or a mixture of technical ceramics. Common impurities may be present.

[0050] Preferably, the retaining element is made entirely of the respective ceramic. Aluminum oxide with a purity of greater than or equal to 99.7% allows for particularly high operating temperatures and achieves good electrical insulation.

[0051] The retaining element is preferably produced using an additive manufacturing process. Production using an additive manufacturing process is particularly advantageous for smaller batch sizes and / or when realizing complex shapes and also allows for the combination of multiple functions in a single component.

[0052] The grooves can be created by cutting out material and do not require grinding as in traditional manufacturing. This also allows for additional freedom in the design of the grooves, such as the aforementioned undercuts and constrictions.

[0053] The invention is particularly suitable for a metallic high-temperature furnace.

[0054] In a metallic high-temperature furnace, the insulation of a process chamber from a furnace shell is essentially made of metal. Such metallic high-temperature furnaces typically have a so-called radiation shield, which is formed by sheets of refractory metal, in particular tungsten, molybdenum, or their alloys, arranged essentially parallel to one another and spaced apart by spacers. For the purposes of the present invention, refractory metals are understood to mean the metals of Group 4 (titanium, zirconium, and hafnium), Group 5 (vanadium, niobium, tantalum), and Group 6 (chromium, molybdenum, tungsten) of the Periodic Table, as well as rhenium. Refractory metal alloys are alloys containing at least 50 at.% of the respective element. These materials exhibit, among other things, excellent dimensional stability at high operating temperatures.Metallic high-temperature furnaces allow for the creation of particularly pure furnace atmospheres, which is not always possible with ceramic or graphite furnaces. Furthermore, they are particularly suitable for heat treatments under vacuum, as there are no outgassing and / or porous surfaces.

[0055] The holding element according to the invention supports the technical possibilities of metallic high-temperature furnaces and improves their economic efficiency.

[0056] Protection is also sought for a method for producing a holding element of the invention.

[0057] For complex geometries and / or small quantities, production is preferably carried out using an additive manufacturing process.

[0058] Binder-based additive manufacturing processes have proven particularly advantageous, with filament printing being particularly preferred.

[0059] To form the groove, no material is deposited at the locations of the future groove or a temporary placeholder, for example a binder without powder, can be deposited.

[0060] For larger quantities, production via powder injection molding is recommended. powder injection molding, PIM). Ceramic powders, as in this case, are usually referred to as ceramic injection molding (CIM). ceramic injection molding, CIM (Cemented Ingot Molding). In this process, a ceramic powder is combined with a binder to create a plasticizable mass that can be processed similarly to plastic injection molding. The resulting green body is debindered and sintered.

[0061] The groove can be formed by the forming tool.

[0062] Furthermore, mechanical insertion of the grooves is possible. This can be done in the green or sintered state of the retaining element.

[0063] Further advantages and benefits of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying figures. The figures show: Fig. 1: a section of a metallic high-temperature furnace Fig. 2: a detail of shielding and heating conductor suspension Fig. 3: a holding element in a first embodiment Fig. 4a-4e: a holding element in a next embodiment Fig. 5a-5c: a holding element in a further embodiment Fig. 6a-6b: a holding element in a further embodiment Fig. 7a-7d: a holding element in a further embodiment Fig. 8a-8c: special designs of grooves Fig. 9: a holding element in a further embodiment

[0064] Figure 1For orientation, this figure shows, schematically and in detail, a typical shield 100 of a metallic high-temperature furnace. The shield 100 is formed from a stack of spaced-apart sheets. In particular, the sheets are made of refractory metal. In the illustration shown, a process chamber continues to the left, which is insulated by the shield 100 from a cooled furnace shell (to the right, not shown). A heating conductor 310 is supported by heating conductor suspensions 320. The heating conductor suspensions 320 are designed here as brackets that hold a strip-shaped heating conductor 310 in position. The specific design of the shield, heating conductor, and heating conductor suspensions can vary.

[0065] Figure 2shows a plan view of a heating conductor suspension 320. A support structure 210 is guided through the shielding 100. The support structure 210 can be designed, for example, as a profile rail or as a tube. The support structure 210 has the task of mechanically holding a heating conductor 310, if necessary by means of a heating conductor suspension 320. The support structure 210, a furnace shell (not shown), and the shielding 100 are conductively connected to one another, thus they are at the same electrical potential, usually ground. ground ) .

[0066] The furnace is heated by means of a heating conductor 310 using electrical resistance heating. For this purpose, the heating conductor 310 must be electrically insulated from the support structure 210. This electrical decoupling is achieved by retaining elements 1, which in the example shown are designed as ceramic sleeves. The ceramic sleeves (four in this example, two per side) extend into the support structure 210 in sections and are held in position by through-passed bolts 330. At the ends of the bolts 330, securing elements such as snap rings or cotter pins secure the assembly. The retaining elements 1 keep the through-passed bolts 330 spaced apart from the support structure 210 and thus insulated.

[0067] A disadvantage of known solutions is that impurities, for example evaporation of heat-treated material, can lead to the formation of conductive paths on holding elements, which can ultimately cause a short circuit between the heating conductor 310 or the heating conductor suspension 320 and the support structure 210.

[0068] The risk of forming a conductive coating exists not only through evaporation of metals due to high vapor pressure (e.g. copper), but also through thermo-chemical transport processes (e.g. via local oxidation --> transport of the oxide gas --> local reduction) and sputtering effects during arcing (e.g. due to incorrect charging).

[0069] Figure 3 shows in a schematic sketch a holding element 1 according to the invention in a first embodiment, by means of which the above-mentioned problems can be overcome. Figure 3shows a cross section along the longitudinal axis of the cylindrical holding element 1 and the bolt 330 running therein.

[0070] The mechanical fastening of the heating conductor suspension 320 to the support structure 210 is effected via the insulating holding element 1. It can be seen that the bolt 330 is spaced from the support structure 210 by a shoulder formed on the holding element 1 and extending into the support structure 210, thus electrically insulating it. A circumferential groove 4 is formed on the cylindrical holding element 1, which prevents the formation of a continuous electrically conductive path between the support structure 210 and the heating conductor suspension 320.

[0071] Figures 4a to 4e show various views of a holding element 1 according to the invention in a next embodiment. Figure 4a a top view, Figure 4b a perspective view, Figure 4c a full cut, Figure 4dA half-section. Half-section means that one half of the drawing shows a cross-section of the component in question, while the other half shows an uncut view.

[0072] In the holding element 1 of the present embodiment, the fastening section 200 is designed in the form of two sleeve-shaped extensions on a part of a surface 3. The fastening section 200 allows insertion into a support structure 210, as shown in Figure 4e shown. The sections of the Figures 4c and 4d are each placed centrally, i.e. along a diameter, through the sleeve-shaped extensions 7.

[0073] The holding element 1 according to this exemplary embodiment has a base body 5 with two sleeve-shaped extensions 7, which can be inserted, for example, into a support structure 210. In this exemplary embodiment, a mechanical connection to a support structure 210 is possible, for example, via bolts that are inserted through the holding element 1 and a support structure 210. To remain with the specific example of the fastening, the aforementioned bolt is then separated from a support structure 210 by a sleeve-shaped extension 7 and is thus electrically insulated from it.

[0074] Spaced apart from the fastening section 200 is a heating conductor receiving section 300 for directly or indirectly receiving a heating conductor (not shown here). The heating conductor receiving section 300 here is an end face of the holding element 1 facing away from the fastening section 200. In the present example, two parallel grooves 4 are formed on one end face of the holding element 1 facing the fastening section 200 and one end face of the holding element 1 facing the heating conductor receiving section 300. The grooves 4 are each circumferential and closed. This creates the situation that at least one groove 4 is formed on a circumferential part of the surface 3 of the holding element 1 lying between the fastening section 200 and the heating conductor receiving section 300, and this groove extends over the entire circumference of the surface 3.

[0075] As can be seen from the presentation of Figure 4bAs can be seen, in the context of this disclosure, a "circumference" along the surface 3 does not necessarily mean the longest path along the surface 3. Rather, in this exemplary embodiment, grooves 4 run along an end face of the holding element 1 facing the fastening section 200, and another pair of grooves 4 runs along an end face of the holding element 1 facing the heating conductor receiving section 300.

[0076] From the presentation in Figure 4cthe width - b - and depth - t - of the groove 4 are derived. An aspect ratio formed from the ratio of the depth - t - to the width - b - is greater than or equal to 1.5; in the present exemplary embodiment, the aspect ratio is approximately 6. The aspect ratio provides a measure of the elongation of the groove 4 and thus a measure of the effectiveness of the groove 4 in preventing the deposition of a precipitate on a groove contour, in particular on a groove base. With an aspect ratio of greater than or equal to 1.5, the occurrence of a continuous electrically conductive path along the groove contour is prevented. There is therefore always an uncoated surface, and thus no conductive path is formed transverse to the groove 4.

[0077] The grooves 4 are designed identically here. Of course, if there are multiple grooves 4, they could differ from one another. It is also not absolutely necessary for a groove 4 to be designed identically throughout its length. For example, a cross-sectional shape could vary along the length of a groove 4.

[0078] The cross-sectional shape of the grooves 4 is rectangular in this embodiment. The depth - t - is measured from the surface 3 to the groove base. In the case of a deviation from the rectangular shape, the narrowest width of the groove is sensibly used as the width - b -, since the narrowest point determines the shading effect of the groove 4.

[0079] In a further development, grooves 4 can also run obliquely to the surface 3, which may further improve the shading effect of the groove 4.

[0080] In Figures 4b and 4dIllustrated with a block arrow is an imaginary path between fastening section 200 and heating conductor receiving section 300 along surface 3. As can be seen, the grooves 4 are arranged such that the imaginary path crosses the grooves 4. This ensures that there is no continuous electrical connection between fastening section 200 and heating conductor receiving section 300. In this exemplary embodiment, it is provided that grooves 4 are formed on an end face facing the fastening section 200 and grooves 4 are formed on an end face facing the heating conductor receiving section 300. As a result, the imaginary path between fastening section 200 and heating conductor receiving section 300 even has to cross a pair of grooves 4 twice, which further improves the effect of the holding element 1 against electrical breakdown.

[0081] Figure 4eshows an assembly situation with two holding elements 1 according to the discussed embodiment in a half section.

[0082] The retaining elements 1 extend into the support structure 210 in sections and are held in position by bolts 330. At the ends of the bolts 330, securing elements such as snap rings or cotter pins secure the assembly. The retaining elements 1 keep the bolts 330 spaced apart from the support structure 210, thus isolating them.

[0083] A heating conductor suspension 320—here in a bracket shape—is mounted on the heating conductor receiving section 300 of the holding element 1. As can be seen from the illustration, an imaginary path between the fastening section 200 and the heating conductor receiving section 300 crosses the grooves 4.

[0084] The arrangement and design of the grooves 4 prevents any deposition of a conductive deposit on the holding element 1 from leading to the formation of a continuous electrically conductive path.

[0085] Figures 5a to 5c show a holding element 1 in another embodiment. Figure 5a a top view, in Figure 5b a perspective view and in Figure 5c a half-section is shown.

[0086] Recurring reference symbols will not be repeated.

[0087] In deviation from the embodiment of the Figures 4a-e Here, the grooves 4 are formed on a lateral surface of the base body 5 of the holding element 1. The circumferential part of the surface 3 lying between the fastening section 200 and the heating conductor receiving section 300 is therefore the lateral surface of the base body 5 of the holding element 1.

[0088] As in Figure 5cVisualized by a block arrow, the imaginary path between the fastening section 200 and the heating conductor receiving section 300 must also cross the grooves 4, whereby the holding element 1 counteracts electrical breakdown in the event of a coating deposit. Thus, an effective separation of the fastening section 200 and the heating conductor receiving section 300 is provided by the groove 4.

[0089] Figures 6a and 6b show an embodiment with a groove 4 on each end face of the base body 5.

[0090] Of course, combinations with regard to the arrangement of the grooves 4 are also possible, i.e. a formation of grooves 4 on the end and lateral surfaces.

[0091] Figures 7a to 7d show views of a holding element 1 according to a further embodiment.

[0092] Figure 7a shows a perspective view, Figure 7b a top view,

[0093] Figure 7ca frontal view as it is along the Figure 7a drawn frontal viewing direction - F - results. Figure 7d shows the holding element 1 in an assembly with a support structure 210.

[0094] In this exemplary embodiment, the holding element 1 is designed as a type of C-shaped clamp. The fastening section 200 is formed on a surface on a back of the C-shape. A support structure can, for example, have corresponding recesses so that the holding element 1 can be inserted or clipped into the support structure. Remaining with the C-shape, the opening of the C-shape forms the heating conductor receiving section 300. A heating conductor or a heating conductor suspension can, for example, be directly inserted into the heating conductor receiving section 300. The heating conductor receiving section 300 often allows a certain amount of play to compensate for thermal expansion of the heating conductor or the heating conductor suspension. Thus, the holding element 1 fulfills several functions particularly advantageously in an integrated component.

[0095] Here, too, a circumferential surface section can be defined between the fastening section 200 and the heating conductor receiving section 300, on which circumferential part of the surface a groove 4 is formed. An imaginary path between the fastening section 200 and the heating conductor receiving section 300 along the surface 3 of the holding element 1 crosses the at least one groove 4, thereby preventing a short circuit caused by any deposits.

[0096] Figure 7dshows a perspective view of the holding element 1 assembled with the support structure 210. The support structure 210 is designed as a clasp with two legs into which the holding element 1 can be inserted or clipped. In this exemplary embodiment, the fastening section 200 forms a contact surface and stop for the support structure 210. The opening of the holding element 1 forms the heating conductor receiving section 300. The circumferential groove 4 is clearly visible between the support structure 210 and the heating conductor receiving section 300.

[0097] Figure 9shows another exemplary embodiment in a sectional and perspective view. Here, the holding element 1 is designed as a feedthrough through a shield 100. In this exemplary embodiment, the holding element 1 is designed to be inserted into or through the shield 100. In an installed situation, the holding element 1 acts as an electrically insulating sleeve in the shield 100, with the shield 100 simultaneously acting as a support structure 210.

[0098] The retaining element 1 of this refinement allows for an electrically insulated passage of a heating connection 340, i.e., an electrical supply line, through the shielding. Separate electrical insulation of this electrical supply line is then unnecessary.

[0099] A heating conductor (not shown) is supplied with power via the heating connection 340. Thus, the inner surface of the holding element 1 of this embodiment can be referred to as a heating conductor receiving section 300 for indirectly receiving a heating conductor.

[0100] The optically significantly different embodiments show that the invention is not tied to a single shape of a holding element.

[0101] Preferably, and as shown in the discussed embodiments, the holding element 1 is monolithic, i.e. formed in one piece.

[0102] Figure 8aschematically shows a groove 4 having a main extension direction - RN - that deviates at least at one point from the direction of the plane normal - N - at that one point on the surface 3 of the holding element 1 at which the groove 4 is formed. In other words, the groove 4 runs obliquely to the surface 3. This configuration can further improve the shading effect of the groove 4.

[0103] Figure 8b shows schematically a holding element with a groove 4 such that the groove 4 has an undercut 6 at least in sections, by means of which undercut 6 a first free groove cross-section at a first distance d1 from the surface 3 is at least in sections smaller than a second free groove cross-section at a second distance d2 from the surface, where d1 < d2. By means of an undercut 6, shading of the groove base can be further improved, since hardly any precipitation occurs beyond the undercut 6.

[0104] In Figure 8c A groove 4 is shown, which has a widening 7 in sections, by which widening 7 a free groove cross-section s is enlarged at least in sections. A widening 7 can, in particular, reduce precipitation on the walls of the groove 4.

Claims

1. A holding element made of ceramic for a high-temperature furnace, said holding element comprising at least one fastening portion (200) formed on a part of a surface (3) of the holding element (1) for mechanically connecting the holding element (1) to a supporting structure (210), at least one heat conductor receiving portion (300) formed on a part of the surface (3) of the holding element (1) for receiving a heat conductor (310), wherein at least one groove (4) having a depth (t) and a width (b) is formed on a peripheral part of the surface (3) of the holding element (1), said peripheral part being located between the fastening portion (200) and the heat conductor receiving portion (300), which groove (4) extends substantially over the entire periphery of the peripheral part of the surface (3) and at least one imaginary path between the fastening portion (200) and the heat conductor receiving portion (300) along the surface (3) of the holding element (1) crosses the at least one groove (4), wherein the groove (4) has an aspect ratio, formed by the ratio of the depth (t) to the width (b), of greater than or equal to 1.5.

2. The holding element as claimed in claim 1, wherein a plurality of grooves (4), in particular two or three grooves (4), is configured.

3. The holding element as claimed in claim 1 or 2, wherein a groove (4) has a depth (t) of between 3 mm and 10 mm.

4. The holding element as claimed in one of the preceding claims, wherein a groove (4) has a width (b) of between 0.25 mm and 3 mm.

5. The holding element as claimed in one of the preceding claims, wherein a groove (4) has at least in some portions an undercut (6), through which undercut (6) at least in some portions a first free groove cross section with a first spacing (d1) from the surface (3) is smaller than a second free groove cross section with a second spacing (d2) from the surface (3), wherein d1 < d2.

6. The holding element as claimed in one of the preceding claims, wherein the groove (4) has at least in some portions a widening (7), through which widening (7) a free groove cross section (s) is enlarged at least in some portions.

7. The holding element as claimed in one of the preceding claims, wherein the groove (4) has a main direction of extent (RN) which at least at one point deviates from the direction of the plane normals (N) at that one point on the surface (3) of the holding element (1) at which the groove (4) is configured.

8. The holding element as claimed in one of the preceding claims, wherein the holding element (1) is configured monolithically.

9. The holding element as claimed in one of the preceding claims, wherein the holding element (1) is configured as a through-passage through a shield (100).

10. The holding element as claimed in one of the preceding claims, wherein the holding element (1) is implemented via a binder-based production method.

11. The holding element as claimed in one of the preceding claims, wherein the holding element (1) is implemented via an additive production method.

12. The holding element as claimed in claim 10, wherein the holding element (1) is implemented via powder injection molding.

13. A high temperature furnace having at least one holding element (1) as claimed in one of the preceding claims.

14. A method for manufacturing a holding element (1) as claimed in one of the preceding claims via a binder-based production method.

15. The method for manufacturing a holding element (1) as claimed in claim 14, wherein the binder-based production method is selected from the group of production methods including, in particular, filament printing and powder injection molding.